I called Hsu and was told to set my VTF2 to 32 and take the plug out. It happens during movies with low bass at about -15 on my HK (whatever that means). My room is about 20 by 15 with vaulted ceilings and lots of open areas behind the listening area. I have the sub positioned in the front right corner. I moved it around a litte tonight and listened to the same movie without the clipping. I also turned down the volume after using an spl meter. Hopefully this does the trick. Thanks for the input.